Mobile companies have closed ranks to fight the threat from Reliance Infocomm’s dirt-cheap WiLL service, but the dramatic decline in STD rates has raised the spectre of a customer exodus from firms like MTNL.

Before analysts finished back-of-the-envelope sums to gauge the impact, the MTNL share lost 2.8 per cent on Dalal Street, ending at Rs 93.55, down from Wednesday’s Rs 96.25. It has surrendered a staggering 12.56 per cent since last week, when it had closed at Rs 106.65.

The jitters also engulfed VSNL, which has long harboured ambitions to offer national long-distance service. Its share was 2.66 per cent weaker at a close Rs 96.65. Reliance, the trigger behind the current telecom churn, also slipped 1.54 per cent at Rs 293 from Rs 297.60.

Market watchers see the two state-owned telecom Goliaths — MTNL and BSNL — taking the hardest knocks once cell tariffs plumb new lows. Karthik Ramakrishnan, an analyst at Sunidhi Consultancy Services, said the fresh salvo from cellular players hits the two telecom majors, which get a big chunk of profits from STD calls.